Hello,
It seems LSIO updated its Plex container which now includes up-to-date intel drivers, working with the last Plex version with HW transcoding and HDR tone mapping support.
If you previously used my 1st script, you can remove it and update Plex container, if you used the one which requires to create an intermediate image, just edit the container configuration, and remove ":opencl" at the end of "Repository" keeping only "linuxserver/plex", then click on apply.
It should download properly everything again and put you back in the original track.
This may leave you with 2 orphan images visible in the docker tab, which can be removed from the advanced view.